Portable power source



FIG. 1 is a bottom view of the portable power source insert of the new design;

FIG. 2 is a front view thereof;

FIG. 3 is a left view thereof;

FIG. 4 is a rear view thereof;

FIG. 5 is a right view thereof; and,

FIG. 6 is a top view thereof. 

CLAIM The ornamental design for a portable power source, as shown and described. 